Updated ms.topic value (#47271)

Assigning this to the correct ms.topic value

Author: kcpitt

docs/ai/index.yml

@@ -6,7 +6,7 @@ summary: Learn to build AI apps with .NET. Browse sample code, tutorials, quicks
 metadata:
   title: AI apps for .NET developers
   description: Samples, tutorials, and education for building AI apps with .NET
-  ms.topic: hub-page
+  ms.topic: landing-page
   ms.service: dotnet
   ms.date: 12/19/2024
   author: alexwolfmsft